Yes Solid state is an important chapter for jee main examination you shouldn't skip any particular topic of this chapter if you skip one topic you'll get problems in multiple question so please don't skip any topic do it thoroughly. Practice as much as you can as practice is the only key which will help you in time management and score good marks.

To know more detailed important topics visit the link below:

https://engineering.careers360.com/articles/jee-main-important-topics-books

I hope my answer helps. All the very best for your future endeavors!